Pure practical reason is the opposite to impure (or sensibly-determined) practical reason and appears in Immanuel Kant's Groundwork of the Metaphysics of Morals.
It is the reason that drives actions without any sensible incentives. Human reasoning chooses such actions simply because those actions are good in themselves; this is the nature of good will, which Kant argues is the only concept that is good without any justification, it is good in itself and is a derivative of a transcendental law which affects the way humans practically reason (see practical philosophy).
Famous quotes containing the words pure, practical and/or reason:
“We may climb into the thin and cold realm of pure geometry and lifeless science, or sink into that of sensation. Between these extremes is the equator of life, of thought, or spirit, or poetry,—a narrow belt.”
—Ralph Waldo Emerson (1803–1882)
“And so we ask for peace for the gods of our fathers, for the gods of our native land. It is reasonable that whatever each of us worships is really to be considered one and the same. We gaze up at the same stars, the sky covers us all, the same universe compasses us. What does it matter what practical systems we adopt in our search for the truth. Not by one avenue only can we arrive at so tremendous a secret.”
—Quintus Aurelius Symmachus (A.D. c. 340–402)
“For some reason a nation feels as shy about admitting that it ever went forth to war for the sake of more wealth as a man would about admitting that he had accepted an invitation just for the sake of the food. This is one of humanity’s most profound imbecilities, as perhaps the only justification for asking one’s fellowmen to endure the horrors of war would be the knowledge that if they did not fight they would starve.”
—Rebecca West (1892–1983)